In the past, there has been proposed a suitable group management control technique which is capable of avoiding car arrival prediction errors in an elevator system in which the speeds and/or accelerations of a plurality of cars are changed according to the loads and/or travel distances of the cars (for example, see a first patent document).
In addition, there has also been proposed an elevator system which is capable of shortening an operation time of each car by changing the maximum speed and/or acceleration of each car according to the load and the moving distance thereof (for example, see a second patent document).
The elevator system described in the above-mentioned first patent document is provided with a prediction time calculation unit to calculate a prediction time at which each car arrives at each floor according to an acceleration set based on a prediction result of the load of the car, and an assignment control unit that assigns a suitable car to a hall call (a car call generated at a hall) in consideration of the calculation result of the prediction time. However, in cases where the prediction result of a car load differs from an actual car load, a suitable car can not be assigned.
Although the elevator system described in the above-mentioned second patent document changes the maximum speed and/or acceleration of each car according to the load and moving distance of the car, it is necessary to take account of the change of the maximum speed and/or acceleration of each car at the time of car assignment in cases where group control is carried out for a plurality of cars.
[First Patent Document]
Japanese-patent-application-laid-open No. 2001-278553
[Second Patent Document]
Japanese-patent-application-laid-open No. 2003-238037